Is this dating thing going anywhere?

Been seeing this guy on and off for a while now and I really don't know if its going anywhere. Maybe I'm being impatient but I've been speaking/seeing him since September and when we can we always try to meet up. Its difficult at the moment though as we both have a lot of work to do for our studies so understandably there's going to be less communication. However, I feel like he seem less interested now? Maybe its me thinking this but he takes ages to respond most days. I told him this bothers me especially when it took him a whole weekend to reply but I could still see him on Fb/Twitter putting status. He said he was sorry and understood why it got me annoyed and he made more of a effort. But now he's taking ages to reply again and I can still see him on Facebook and stuff. Shall I take it that he's not that interested? Or shall I just see how things go until i come back home for good? ***Also we have slept together once, he's told me before how he feels about me, and that apparently wants something to come out of it